It is generally well known that conduits or pipes, particularly underground pipes, which are employed for conducting fluids, for example, sanitary sewer pipes, storm sewer pipes, water lines and gas lines, frequently require repair due to fluid leakage. The leakage may be inwardly, from the environment into the interior or conducting part of the pipe, or outwardly, from the conducting part of the pipe into the surrounding environment. Leakage of this type may be due to improper initial installation of the pipe, deterioration of the pipe itself due to normal aging or the effects of conveying corrosive or abrasive materials, cracking of the pipe or pipe joints due to environmental conditions, such as earthquakes, the movement of large vehicles or similar natural or man-made vibrations, or any other such causes. Regardless of the cause, such leakage is undesirable, at best, and may result in waste of the fluid being conveyed by the pipe, damage to the surrounding environment and the possible creation of dangerous public health hazards.
Because of ever increasing labor and machinery costs, it is becoming increasingly more difficult, at least economically, to dig up and replace underground pipes or portions or sections of such underground pipes which may be leaking. As a result, various methods have been devised for the in situ repair or rehabilitation of existing pipes, thereby avoiding the expense and hazards associated with digging up and replacing the pipes or pipe sections.
One of the more successful pipe repair or rehabilitation processes which is currently used is called the Insituform Process and is described in U.S. Pat. No. 4,009,063, Wood; U.S. Pat. No. 4,064,211, Wood, and U.S. Pat. No. 4,135,958, Wood, the contents of which are incorporated herein by reference. It involves the use of an elongated flexible tubular liner comprised of a felt fabric or foam or similar flexible material which has been impregnated with a thermosetting synthetic catalyzed resin, which is installed within the existing pipe utilizing an inverting or everting process, as is known to those skilled in the art. Once the flexible liner is installed in place within the pipe, the liner is pressurized from within, preferably utilizing a fluid such as water, to force the liner radially outwardly to engage and conform to the interior surface of the pipe and to force some of the impregnated resin into any cracks or interstices within the walls of the pipe. The resin is then cured to form a relatively hard, tight fitting, rigid pipe lining which effectively seals any cracks and repairs any pipe or pipe joint deterioration to prevent further leakage either into or out of the pipe. The cured resin liner also serves to strengthen the existing pipe walls to provide added structural support for the surrounding overburden. The apparatus of the present invention and its manner of use will be here described in connection with the installation of a liner of the above type, but it will be appreciated that that is by way of exemplification only.
Many pipes to be relined have leading and trailing ends which are directly or easily accessible. However, other pipes have only one end directly or easily accessible, and it is to the lining of this latter type of pipe that the instant invention is particularly directed. Typical of such one-end accessible pipes are service pipes associated with main sewage pipes. Typically, the main sewer pipe is in fluid communication with each house or building in the residential or commercial area for receiving sewage therefrom and transporting the sewage to a treatment center. A service pipe is transversely connected to the main pipe and provides the means for transporting the sewage to the main pipe, as is understood by those skilled in the art.
There presently exists a need for an effective and economical way to reconstruct service pipes which extend between commercial or residential buildings and a main sewer pipe. My prior U.S. Pat. No. 5,108,533 of Apr. 28, 1992, entitled "Method and Combination For Installing a Liner Within a Service Pipe Transversely Connected to a Main Pipe", the contents of which are here incorporated by reference, is directed to just such a relining of a service pipe. The present invention in its more specific aspects constitutes an improvement over what is disclosed in that patent.
More specifically, the apparatus here disclosed and claimed comprises a structure readily movable to its place of use and which comprises, in an efficient and self-contained manner, the apparatus necessary to form a liner of a type suitable for insertion into a service pipe, to move that liner into position in the service pipe and to supply to that liner, in an effective and functionally flexible manner, the fluids appropriate to inflate the liner both before and after it has been inserted, and then to withdraw from the liner all of those elements which are not to remain in that service pipe. Thus the apparatus includes winch means for controlling the movement of the elements, and particularly the evertable elements, which participate in liner formation and insertion, and it also includes conduit means associated with the tube eversion portion of the apparatus for supplying fluid to the remote end of the lining tube after the tube is in place, thereby to facilitate the curing of the impregnating resin. The conduit means may be moved to a withdrawn position, where it does not interfere with the eversion of a liner element when that eversion is taking place, but is thereafter movable along the length of the everted element substantially to said remote end thereof, after which fluid is supplied to the interior of the everted element via the leading end of that conduit means.
It is the prime object of the present invention to devise an apparatus which transports to the point of use a maximum amount of the equipment needed to install a liner within a conduit, especially a service pipe.
It is a further object of the present invention to devise such an apparatus having improved means for supplying fluid to the interior of the liner assembly, which fluid-supplying means may be readily controlled and adapted to perform specifically different functions as required, and to facilitate simultaneous lining operations at different locations.
It is yet another object of the present invention to devise an apparatus for everting a tube which also has mounted thereon or directly associated therewith such auxiliary equipment as is appropriate for the carrying out of tube formation and insertion in an efficient, effective and flexible manner.